1 Field of the Invention
The present invention relates generally to a wrench, and is more specifically related to an anti-slip wrench with simple structure and easy manipulation
2. Background of the Invention
For manipulating of a conventional wrench, it is necessary to press the surface of the handle with the thumb while holding the handle of the wrench with the palm. Generally, thumb will slide easily along the longitudinal or further transverse direction of the handle, if the friction between thumb and the surface is not sufficient. Furthermore, how the manipulation of the conventional wrench goes usually depends on conditions of the user's hands, for example, oily or sweated hands could not work properly upon the wrench.
A design patent application no. D116658, filed in Taiwan, R.O.C., entitled “Wrench (I)” discloses a wrench, which is formed of two recesses at two ends of a handle thereof, for easy manipulation. The recesses offer the placements for the thumb though, the longitudinal slid between thumb and the recesses, which results in the failure of concentrative application of the force, still happens.
In addition, a solution to the slippery-proof problem for the conventional wrench is to coat a baked anti-slip painted finish or to add extra elements on it. However, adding the coating process or making extra elements may cause the increase the primary costs due to extra materials, structures or process steps, also may bring about a change to production or prolong the manufacture period so as to result in competition weakening of enterprises.